For sure will keep doing battle voices in RPGs. A solution might be to have the most important cutscene voiced only, I thought also about that. For games like Loren voicing would be literally impossible, since they're really too big

I will admit that when I bought Bionic Heart (the first one), one of the draws was that there was voice acting in it- it's pretty rare with English-language visual novels.
BUT, on the other hand, I really play visual novels for the story, so more text and/or more ways to change the story (which would bloat the amount of text- like the different personality-based responses in Loren) would trump voice acting for me.
...I would probably still purchase an add-on for Bionic Heart 2 to add voices, though XD

I am relatively intrigued by the idea of voicing just the big important scenes, though. It reminds me a bit of an RPG/Visual Novel type series that I've played before (Persona 3/4), where there are all these sidequests where you get to know characters, with only a few generic lines here and there for most of the quest- but then if you reach the end of the quest, the end scene is pretty much fully-voiced (their protagonists are silent except for battle voicing in the RPG stuff), which kind of feels like a reward.

Tellah wrote:
I am relatively intrigued by the idea of voicing just the big important scenes, though. It reminds me a bit of an RPG/Visual Novel type series that I've played before (Persona 3/4), where there are all these sidequests where you get to know characters, with only a few generic lines here and there for most of the quest- but then if you reach the end of the quest, the end scene is pretty much fully-voiced (their protagonists are silent except for battle voicing in the RPG stuff), which kind of feels like a reward.

Another "technique" is to do like in Bioware games, Dragon Age ones, where each choice is the full sentence that the players says, so basically the playing character is never voiced, nor the narrator, so as you can imagine that saves a big amount of work.